Processing black mass from lithium ion batteries

Abstract

The present invention relates to the recycling of used lithium ion batteries and provides a method and a plant for processing black mass derived from lithium ion batteries.

Description

[0001] BASF SE B25.184P-WO

[0002] 67056 Ludwigshafen am Rhein 25.09.2025 / lg / np / jl

[0003] Processing black mass from lithium ion batteries

[0004] Field of the invention

[0005] The present invention relates to the recycling of used lithium ion batteries and provides a method and a plant for processing black mass derived from lithium ion batteries.

[0006] Background

[0007] Lithium ion battery materials contain valuable metals such as lithium, aluminum, copper, nickel, cobalt, and / or manganese that can be recovered and recycled to conserve natural resources. Processes for recycling lithium ion battery materials generally comprise mechanical comminution of lithium ion batteries, lithium ion battery waste, lithium ion battery production scrap, lithium ion cell production scrap, or lithium ion cathode active material to obtain black mass, a particulate material comprising the active components of the battery electrodes such as graphite and cathode active material, which may also include impurities from the casing, electrode foils, cables, separator, and electrolyte. The black mass then is further processed to recover the valuable metals, for instance, by hydrometallurgical treatment.

[0008] Black mass is a highly toxic powder, and the particles are very fine and volatile. When it comes to unloading, transferring and loading black mass, any dust emissions into the atmosphere must be avoided to protect operators against the risk of contamination. The black mass is generally stored in big bags. Unloading the black mass from the big bag and transferring it to further recycling steps therefore requires particular caution. Also, the composition of the black mass varies between individual big bags and even within a single big bag. There is a need for a process for handling black mass that avoids risks to workers and the environment and allows for standardizing the composition of the black mass.

[0009] WO 2023 / 148174 A1 discloses a method and a device for processing black mass derived from lithium ion batteries. Black mass is leached in a continuously stirred reaction vessel comprising an acidic aqueous solution at a pH less than 0. In the working examples, black mass was suspended in deionized water under an atmosphere of argon and acid was slowly added to the suspension under stirring.

[0010] Summary of the invention

[0011] The present disclosure provides a method and a plant for processing black mass derived from lithium ion batteries. The process involves providing particulate black mass in a storage container, e.g., a big bag, a drum, a bunker, or a silo, within a controlled environment, conveying particulate black mass from the storage container into a mixing vessel within a controlled environment, mixing the particulate black mass and water in the mixing vessel with stirring to produce an aqueous suspension of black mass particles, transferring the suspension into one or more storage tanks, and continuously keeping the suspension in motion by stirring and / or recirculation. For recovering valuable metals, the suspension is dosed into a leaching reactor, optionally mixed with cathode active material (CAM) and / or mixed metal hydroxide precipitate (MHP) and subjected to hydrometallurgical treatment. The plant for processing black mass of the present disclosure comprises means for safely conveying particulate black mass from a storage container into a mixing vessel, a mixing vessel comprising means for agitating the vessel contents, at least three storage vessels, each vessel comprising means for agitating the vessel contents, and a leaching reactor. The at least three storage vessels are suitable for storing aqueous suspension of particulate matter, namely black mass (BM), cathode active material (CAM), and / or mixed metal hydroxide precipitate (MHP). Brief description of the drawing

[0012] Fig. 1 shows a plant for processing black mass according to an embodiment of the invention.

[0013] Detailed description

[0014] The present disclosure provides a method for processing black mass derived from lithium ion batteries. The process involves providing particulate black mass in a storage container, e.g., a big bag or a drum, placed within a confined space featuring a controlled atmosphere, conveying particulate black mass from the storage container into a mixing vessel located within the confined space, mixing the black mass and water in the mixing vessel with stirring to produce an aqueous suspension of black mass particles, transferring the suspension into one or more storage tanks, and continuously keeping the suspension in motion in the storage tank(s) by stirring and / or recirculation using a suitable pump system. For recovering valuable metals, the suspension is removed from the storage tank and dosed into a leaching reactor, optionally mixed with cathode active material (CAM) and / or mixed metal hydroxide precipitate (MHP), and subjected to hydrometallurgical treatment.

[0015] In the present disclosure, the term “controlled environment” means a confined space featuring a controlled atmosphere. The term “controlled atmosphere” means that air pressure within the confined space is kept below ambient pressure, so that no black mass dust can escape from the confined space to the environment in case of a leakage, and atmospheric humidity is controlled to be within a predefined range to prevent agglomeration of the black mass particles. In some embodiments, air pressure within the confined space is kept from 15 Pa to 50 Pa, for instance, from 20 Pa to 40 Pa, e.g., 20 Pa to 30 Pa below ambient pressure. In some embodiments, humidity of the air within the confined space is kept within a range of 45% to 20% relative humidity (RH).

[0016] In the present disclosure, the term “black mass” refers to materials derived from, for example, a lithium ion battery, lithium ion battery waste, lithium ion battery production scrap, lithium ion cell production scrap, lithium ion cathode active material, and / or combinations thereof by mechanical processes such as mechanical comminution. For example, black mass may be derived from battery scrap by mechanically treating the battery scrap to obtain the active components of the electrodes such as graphite and cathode active material and may include impurities from the casing, electrode foils, cables, separator, and electrolyte. In some examples, the battery scrap may be subjected to a heat treatment to pyrolyze organic (e.g., electrolyte) and polymeric (e.g., separator and binder) materials. Such a heat treatment may be performed before or after mechanical comminution of the battery material.

[0017] Lithium ion batteries can comprise a variety of different cathode materials, for instance, lithium cobalt oxide (LiCoCh), lithium iron phosphate (LiFePCU or LFP), lithium manganese oxide (LiMn2O4 spinel, or Li2MnO3-based lithium-rich layered materials, LMR-NMC), lithium nickel manganese cobalt oxide (LiNiMnCoCh or NMC) and lithium nickel cobalt aluminum oxides (LiNixCoyAIzCh with x + y + z = 1 or NCA).

[0018] Lithium ion batteries may be disassembled, after discharging and optionally drying them, punched, milled, for example in a hammer mill, and / or shredded, for example in an industrial shredder. From this kind of mechanical processing the active material of the battery electrodes may be obtained. A light fraction such as housing parts made from organic plastics and aluminum foil or copper foil may be removed, for example, in a forced stream of gas, air separation or classification.

[0019] Battery scraps may stem from, e.g., used batteries or from production waste such as off-spec material. In some embodiments a battery material is obtained from mechanically treated battery scraps, for example from battery scraps treated in a hammer mill or in an industrial shredder. Such material may have an average particle diameter (D50) ranging from 1 pm to 1 cm, such as from 1 pm to 500 pm, for example, from 3 to 250 pm. Larger parts of the battery scrap like the housings, the wiring and the electrode carrier films may be separated mechanically such that the corresponding materials may be excluded from the battery material that is employed in the process.

[0020] Mechanically treated battery scrap may be subjected to a solvent treatment to dissolve and separate polymeric binders used to bind the transition metal oxides to current collector films, or, e.g., to bind graphite to current collector films. Suitable solvents are N-methylpyrrolidone, N,N-dimethyl-formamide, N,N- dimethylacetamide, N-ethylpyrrolidone, and dimethylsulfoxide, in pure form, as mixtures of at least two of the foregoing, or as a mixture with 1 % to 99 % by weight of water.

[0021] Mechanically treated battery scrap may be subjected to a heat treatment in a wide range of temperatures under different atmospheres. The temperature range is usually in the range of 100°C to 900°C. Lower temperatures below 300°C may serve to evaporate residual solvents from the battery electrolyte, at higher temperatures the binder polymers may decompose while at temperatures above 400°C the composition of the inorganic materials may change as some transition metal oxides may become reduced either by the carbon contained in the scrap material or by introducing reductive gases. In some embodiments, a reduction of lithium metal oxides may be avoided by keeping the temperature below 400°C and / or by removing carbonaceous materials before the heat treatment.

[0022] In some embodiments, the battery material comprises at least one chosen from lithiated nickel cobalt manganese oxide, lithiated nickel cobalt aluminum oxide, lithium metal phosphate, lithium ion battery scrap, black mass derived from a lithium ion battery, and combinations there.

[0023] In some embodiments, the battery material comprises lithium metal phosphate of formula LixMPCU, wherein x is an integer greater than or equal to one, and M is chosen from metals, transition metals, rare earth metals, and combinations thereof.

[0024] In some embodiments, the battery material comprises lithiated nickel cobalt manganese oxide of formula Lii+x(NiaCobMncM1d)i-xO2, wherein M1 is chosen from Mg, Ca, Ba, Al, Ti, Zr, Zn, Mo, V and Fe, zero < x < 0.2, 0.1 < a < 0.95, zero < b < 0.9 (such as 0.05 < b < 0.5), zero < c < 0.6, zero < d < 0.1 , and a + b + c + d = 1 . Exemplary lithiated nickel cobalt manganese oxides include Li(i+x)[Nio.33Coo.33Mno.33](i-x)02, Li(i+X)[Nio.5Coo.2Mno.3](i-x)02, Li(i+X)[Nio.6Coo.2Mno.2](i-x)02, Li(i+X)[Nio.7Coo.2Mno.3](i-x)02, Li(i+x)[Nio.8Coo.iMno.i](i-x)02 each with x as defined above, and Li[Nio.85COo.13Alo.02]02.

[0025] In some embodiments, the battery material comprises lithiated nickel-cobalt aluminum oxides of formula Li[NihCo lj]O2+r, wherein h ranges from 0.8 to 0.90, i ranges from 0.1 to 0.3, j ranges from 0.01 to 0.10, and r ranges from zero to 0.4.

[0026] In some embodiments, the battery material comprises nickel, cobalt, manganese, copper, aluminum, iron, phosphorus, or combinations thereof.

[0027] In some embodiments, the battery material comprises LixMO2 wherein x is an integer greater than or equal to one, and M is chosen from metals, transition metals, rare earth metals, and combinations thereof.

[0028] In the present disclosure, the term cathode active material (CAM) means a material being present in a cathode of a lithium ion battery as the active component. The CAM may either be an off-spec material from CAM production, a material retrieved from an off-spec cathode, or a CAM material retrieved from a lithium ion battery. The CAM is either a layered oxide (such as lithium cobalt oxide) or a spinel (such as lithium manganese oxide). Examples of cathode active materials include lithium cobalt oxide (LiCoCh), lithium manganese oxide (LiMn2O4), and lithium nickel manganese cobalt oxide (LiNiMnCoCh or NMC). In some embodiments, the material comprises one or more chosen from lithiated nickel cobalt manganese oxide and lithiated nickel cobalt aluminum oxide. In some embodiments, the material comprises lithiated nickel cobalt manganese oxide of formula Lii+x(NiaCobMncM1d)i-xO2, wherein M1is chosen from Mg, Ca, Ba, Al, Ti, Zr, Zn, Mo, V and Fe, zero < x < 0.2, 0.1 < a < 0.95, zero < b < 0.9 (such as 0.05 < b < 0.5), zero < c < 0.6, zero < d < 0.1 , and a + b + c + d = 1. Exemplary lithiated nickel cobalt manganese oxides include Li(i+x)[Nio.33Coo.33Mno.33](i-x)02, Li(i+X)[Nio.5Coo.2Mno.3](i-x)02,

[0029] Li(i+X)[Nio.6Coo.2Mno.2](i-x)02, Li(i+X)[Nio.7Coo.2Mno.3](i-x)02,

[0030] Li(i+x)[Nio.8Coo.iMno.i](i-x)02, each with x as defined above, and Li[Nio.85COo.13Alo.02]02.

[0031] In some embodiments, the material comprises lithiated nickel-cobalt aluminum oxides of formula Li[NihCo lj]O2+r, wherein h ranges from 0.8 to 0.95, i ranges from 0.1 to 0.3, j ranges from 0.01 to 0.10, and r ranges from zero to 0.4.

[0032] In some embodiments, the material comprises lithiated manganese oxides of formula Li(i+x)Mn2-x-y-zMyMzO4, wherein x ranges from zero to 0.2; y+z ranges from zero to 0.1 ; and M’ is chosen from Al, Mg, Fe, Ti, V, Zr and Zn.

[0033] In some embodiments, the material comprises a compound of formula xLi(i+i / 3)M(2 / 3)O2 yLiMO2 zLiM’Ch, wherein M comprises at least one metal of Mn, Ni, Co of oxidation state +4 , M’ is at least one transition metal, and 0 < x < 1 , 0 < y < 1 , 0 < z < 1 and x + y + z = 1.

[0034] In the present disclosure, the term mixed hydroxide precipitate (MHP) means a mixture of metal hydroxides, hydroxycarbonates, and / or carbonates comprising nickel hydroxide, cobalt hydroxide and other metals, e.g., manganese. In some embodiments, the MHP is obtained by precipitating metal hydroxides from a metal salt solution. MHP typically comprises from 0 to 2 wt% Li, from 10 to 50 wt% Ni, from 0.1 to 20 wt% Co, from 0.01 to 15 wt% Mn. Moisture content generally is in the range of from 20 to 60 wt%, relative to the total weight of MHP. A typical range for D(50) is from 1 to 150 pm. In some embodiments, the MHP is an intermediate nickel product produced from laterite nickel ore, which contains both nickel and a small percentage of cobalt. MHP is typically produced using a high-pressure acid leaching (HPAL) process. The mixed hydroxide precipitate (MHP) mostly consists of nickel hydroxide, but also contains valuable cobalt hydroxides and various other impurities, the main one being manganese. Ni content typically is 34-55 wt%, Co content typically 1- 4.5 wt%.

[0035] At the start of the process of the present disclosure, the black mass is provided in particulate form, i.e. , as a powder, in a storage container, e.g., a big bag, a drum, a bunker, or a silo. As black mass is hygroscopic, it is important that this powder does not come in contact with humidity to avoid any risk of clogging. Black mass dust is toxic and carcinogenic, and therefore it is imperative to prevent black mass dust from escaping into the environment and to prevent employees from getting into contact with black mass dust. Therefore, a controlled environment is used to convey particulate black mass from the storage container is into a mixing vessel. The conveying step is performed within a confined space featuring reduced air pressure and controlled humidity. Air pressure within the confined space is kept below ambient pressure, so that no black mass dust can escape from the confined space to the environment in case of a leakage. In some embodiments, air pressure within the confined space is kept from 15 Pa to 50 Pa, for instance, from 20 Pa to 40 Pa, e.g., 20 Pa to 30 Pa below ambient pressure. Humidity of the air within the confined space is kept within a range of 45% to 20% relative humidity (RH) to prevent agglomeration of the black mass particles.

[0036] The step of conveying particulate black mass from the storage container into a mixing vessel is performed using suitable conveyors. In case of a bunker or a silo, direct conveying from the outside of the confined space through pipes or other powder conveying systems can be used, especially, when a continuous process is implemented. One example is the interconnection of two plants, a black mass production plant and a black mass refinery plant. The step of conveying particulate black mass from the big bag or drum into a mixing vessel is performed using suitable powder conveyors present in the confined space.

[0037] In one embodiment of the process, a pneumatic transfer cyclone with a suction lance is used. The suction lance pierces a big bag, or is inserted into an opened drum, and a chamber above the mixing vessel is filled using negative pressure, then the chamber is emptied into the mixing vessel. This system is a precise conveying system for fine powders.

[0038] In another embodiment of the process, a screw conveyor is used to transfer the particulate black mass from the big bag into the mixing vessel.

[0039] In still another embodiment, a big bag is suspended above a funnel connected to the mixing vessel, the bottom of the big bag is cut open, and the black mass falls into the mixing vessel through the funnel.

[0040] In the mixing vessel, the black mass is mixed with water with stirring to produce an aqueous suspension of black mass particles. In some embodiments, mixing and dispersing of the black mass is performed as a batch process. In other embodiments, mixing and dispersing of the black mass is performed as a continuous process.

[0041] In one embodiment of the process, water is filled into the mixing vessel first, then black mass is added. This has the advantage that the mixture initially can be easily stirred, and stirring then gradually becomes harder due to the increasing solids content of the mixture; the other way round would be more difficult. However, splashing can occur when the black mass is added from above, which may lead to clogging of the dosing funnel over time. In another embodiment of the process, black mass is filled into the mixing vessel first, then water is added.

[0042] In some embodiments of the process, temperature in the mixing vessel is kept in the range of from 10°C to 95°C, e.g., from 20°C to 50°C, during the mixing step. In some embodiments of the process, mixing is performed at ambient temperature.

[0043] In some embodiments of the process, specific power input into the fluid in the mixing vessel is in the range of from 0.05 to 5.0 W / L, for instance, 0.1 to 1.0 W / L. In some embodiments of the process, mixing power is in the range of from 0.5 kW to 250 kW, e.g., from 5 kW to 110 kW, or from 7.5 kW to 55 kW. In some embodiments of the process, speed of the mixer or disperser is in the range of from 100 rpm to 3,600 rpm, e.g., 750 rpm to 3,000 rpm.

[0044] In some embodiments of the process, an aqueous suspension of black mass with a solids content in the range of from 20 wt% to 50 wt%, for instance, 20 wt% to 40 wt%, e.g., 20 wt% to 30 wt%, relative to the total weight of the aqueous suspension, is produced.

[0045] Producing an aqueous suspension of black mass particles offers several advantages over using black mass powder, for instance, that a suspension can be conveyed more easily and with a lower safety risk than a black mass powder.

[0046] Black mass has an inhomogeneous composition and representative sampling of the powder is difficult. This is due to the inhomogeneity of the battery feed that is fed into the black mass production. The black mass can vary greatly even within a single big bag. Producing an aqueous suspension of black mass particles involves suspending a larger amount of black mass in water, mixing it and thus homogenizing it. This homogenization of the feed also allows for determining a more representative composition of the black mass. In powder form, sampling can only be done by the less representative spear sampling (puncturing the big bags at different points). Composition between individual samples taken from the same big bag can vary substantially. For instance, nickel content may differ by up to 7%. As the chemical composition of the black mass in the big bag cannot be determined accurately (see above, spear sampling), the chemical composition of the suspension cannot be precisely adjusted using black mass and water. The process of the present disclosure allows for controlling the chemical composition of the black mass suspension in the hydrometallurgical treatment stage by dosing different feed streams to the leaching reactor.

[0047] In some embodiments, the process further comprises dosing the suspension of black mass particles into a leaching reactor, optionally also dosing cathode active material (CAM) and / or mixed metal hydroxide precipitate (MHP) into the leaching reactor, adding an acid to the leaching reactor, and producing an aqueous acidic solution containing valuable metals leached from the black mass, and, as the case may be, from the CAM and / or MHP. In some embodiments, the acid is sulfuric acid.

[0048] In some embodiments of the process, aqueous suspensions of MHP or CAM also are provided in agitated storage tanks. All three components can be dosed into the leaching reactor and mixed to control the composition of the suspension.

[0049] The chemical composition of the aqueous suspension of black mass particles in the mixing vessel is determined. The suspension then is pumped into one or more storage tanks. In one embodiment of the process, the contents of the mixing vessel are distributed between two or three storage tanks. The feed from the mixing vessel to the storage tanks is carried out via a suitable pipe and valve system.

[0050] In some embodiments of the process, the aqueous suspension of black mass particles is produced from NMC black mass. In other embodiments of the process, the aqueous suspension of black mass particles is produced from LFP black mass. In still other embodiments of the process, the aqueous suspension of black mass particles is produced from a blend of NMC black mass and LFP black mass. In some embodiments, the content of LFP black mass in the blend is in the range of from 5 wt% to 20 wt%, relative to the total weight of the blend.

[0051] In one embodiment of the process, the composition of the suspension is checked by means of pH measurement. As an example, for a blend of LFP black mass with NMC black mass, a fairly uniform feed is necessary in the leaching stage. Too large a proportion of LFP material is unfavorable, as the iron components will precipitate as impurities, increasing the filter cake volume and thus placing a strain on the capacity of the filter press. It is therefore advisable to keep the LFP proportion constant and low. NMC black mass reacts with water to form an alkaline solution; the suspension of black mass particles from pyrolyzed NMC black mass has a pH of 10-11. CAM behaves similarly due to its oxidic structure. On the other hand, the pH of a suspension of LFP black mass is 7 (about neutral), because it does not contain any soluble basic components. The pH can now be measured in all tanks of the mixing system. If the pH is not high enough in the storage tank or in the leaching reactor, the suspension can be supplemented from a tank containing a suspension with a high pH (which contains less LFP and more CAM or NMC black mass). Measurement of pH is the fastest and simplest measurement method suitable for this task. When non-pyrolyzed black mass is used, the pH of both the NMC black mass suspension and LFP black mass suspension shifts slightly downwards. The LFP black mass suspension then is slightly acidic (due to the formation of HF), and pH of the NMC black mass suspension is around 8.8. The trend therefore remains the same; the pH value can be used in the same way to control the composition within the system.

[0052] In another embodiment of the process, the composition of the suspension is checked by measuring the redox potential of the suspension. When the redox potential of the suspension of black mass particles is outside a defined range, a CAM suspension is added to the leaching reactor from the CAM suspension storage tank. CAM has reductive properties and influences the success of the leaching, during which the redox potential is checked. In another embodiment of the process, the composition of the suspension is checked using XRF measurements. XRF measurements can be used as an online analysis method to check the suspensions for Fe or P and thus estimate the LFP content.

[0053] The feed stream to the leaching reactor can be composed as desired with a precise and clearly definable chemical composition, by pumping the required quantities of the individual suspensions from the storage tanks directly into the leaching reactor via a suitable pipe and valve system. In one embodiment, the blending of the individual suspensions is performed automatically.

[0054] The suspension of the black mass particles (as well as the suspensions of CAM and MHP, respectively) is continuously kept in motion in the storage tank and in the pipe system of the plant by stirring and / or by recirculation using a suitable pump system. The black mass particles tend to settle quickly, and the suspension is only stable for a short time. To ensure continuous movement, a flow rate of the suspension must not fall short of a critical flow velocity. Critical flow velocity must be reached to avoid sedimentation. Critical flow velocity of the suspension of black mass particles at which black mass begins to sediment is 0.9 m / s. In some embodiments of the process, flow velocity of the suspension of black mass particles is kept within a range of from 0.9 m / s to 2.3 m / s, e.g., 1 .2 m / s to 2.0 m / s.

[0055] The present disclosure also provides a plant for processing black mass and performing the method of the present disclosure.

[0056] The plant for processing black mass of the present disclosure comprises means for safely conveying particulate black mass from a storage container into a mixing vessel, a first mixing vessel comprising means for agitating the vessel contents, at least three storage tanks configured for storing an aqueous suspension of particles, each tank comprising means for agitating the vessel contents, and a leaching reactor. The means for safely conveying particulate black mass from a storage container into a mixing vessel and the first mixing vessel comprising means for agitating the vessel contents are located within a confined space featuring reduced atmospheric pressure and controlled atmospheric humidity. In an embodiment of the plant, at least one of the at least three storage tanks is configured for storing an aqueous suspension of black mass. In an embodiment of the plant, at least one of the at least three storage tanks is configured for storing an aqueous suspension of cathode active material (CAM). In an embodiment of the plant, at least one of the at least three storage tanks is configured for storing an aqueous suspension of mixed metal hydroxide precipitate (MHP).

[0057] The storage container, e.g., a big bag or a drum, also is placed in the confined space when the plant is performing the method of the present disclosure. For introducing the storage container into the confined space, a sluice or air shower is provided in a wall of the confined space.

[0058] In some embodiments, the means for safely conveying particulate black mass from a storage container into a mixing vessel comprise suitable conveyors. In one embodiment, the conveyor comprises a pneumatic transfer cyclone with a suction lance. In another embodiment, the conveyor comprises a screw conveyor. In still another embodiment, the means for safely conveying particulate black mass from a storage container into a mixing vessel comprise a gibbet or hoist for suspending a big bag, and a funnel connected to the mixing vessel, configured for receiving the contents of the big bag and guiding them into the mixing vessel.

[0059] The plant of the present disclosure features a first mixing vessel configured for receiving particulate black mass and water and mixing them to produce a suspension of black mass particles. The first mixing vessel comprises means for agitating the vessel contents. In some embodiments, the means for agitating the vessel contents comprise a mechanical stirrer. Examples of suitable mechanical stirrers include paddle mixers, propeller mixers, horseshoe mixers, impeller mixers, and turbine mixers. In some embodiments, the means for agitating the vessel contents comprise a disperser. Examples of suitable dispersers include shear rings, dispersers comprising a rotor-stator system, and mixing heads generating both a vertical and a horizontal fluid stream. The vertical sub-stream is directed directly to the bottom of the mixing vessel where it is split and circulates the contents of the entire vessel. A second sub-stream is deflected horizontally and passes through the dispersion zone. Solid components are comminuted and distributed homogeneously.

[0060] In some embodiments, the first mixing vessel also is configured for receiving particulate CAM and water and mixing them to produce a suspension of CAM particles.

[0061] In some embodiments, the plant of the present disclosure additionally features a second mixing vessel configured for receiving particulate MHP and water and mixing them to produce a suspension of MHP particles. In some embodiments, the second mixing vessel also is located within the confined space featuring reduced atmospheric pressure and controlled atmospheric humidity.

[0062] The plant of the present disclosure comprises at least three storage tanks, each tank comprising means for agitating the tank contents. In some embodiments, the plant comprises one storage tank for a suspension of black mass particles, one storage tank for a suspension of CAM particles, and one storage tank for a suspension of MHP particles. In some embodiments, the plant comprises more than one storage tank for a suspension of black mass particles, e.g., two or three storage tanks for a suspension of black mass particles. The storage tanks comprise means for agitating the tank contents. In some embodiments, the means for agitating the tank contents comprise a mechanical stirrer. In some embodiments, the means for agitating the tank contents comprise circulation pumps. In further embodiments, the means for agitating the tank contents comprise static mixers.

[0063] In some embodiments of the plant, the volume of the storage tank(s) for the suspension of black mass particles amounts to 2-3 times the volume of the mixing vessel. In some embodiments of the plant, the volume of the storage tank(s) for the suspension of black mass particles amounts to 3 times the volume of the mixing vessel. This allows for suspensions produced in different mixing batches to be mixed in the storage tank, thus controlling the chemical composition of the suspension in the storage tank(s).

[0064] In some embodiments of the plant, the storage tanks are located outside the confined space featuring reduced atmospheric pressure and controlled atmospheric humidity.

[0065] The plant of the present disclosure also comprises at least one leaching reactor. The leaching reactor is configured to receive suspensions from the storage tanks. In the leaching reactor, valuable metals are leached from the black mass with acid, e.g., sulfuric acid. In some embodiments of the plant, the leaching reactor also is located outside the confined space featuring reduced atmospheric pressure and controlled atmospheric humidity. In some embodiments of the plant, a plurality of leaching reactors is present. In some embodiments, the reactors form a leaching cascade.

[0066] The entire plant is built in such a way that the suspension remains in constant motion. Additional structural measures are taken to avoid, for example, blocking of a reactor outlet (e.g., by means of piston or mushroom valves). Dead spaces also are avoided.

[0067] To ensure continuous movement of the suspension, there is a safety concept that takes effect in the event of an incident, with the aim of allowing the suspension to continue to move and achieving maximum safety gains with minimal measures. Otherwise, the pipes would quickly become clogged with black mass and the plant would have to be stopped and flushed. This would lead to downtime and reduced plant availability. In some embodiments of the plant, volume flow in the plant is monitored in order to avoid clogging of the pipes. If it is observed that the flow rate is steadily decreasing over a longer period of time, this indicates that the black mass is settling. In some embodiments of the plant, an A / B pump system prevents pump failures, i.e. , a second pump takes over if the first pump fails. This means that two functional and installed pumps are always kept ready so that if the active pump fails, the second can take over immediately and without delay.

[0068] Black mass particles are very hard and promote abrasion of components, pumps and pipes. In some embodiments of the plant, pipes are lined, e.g., with PFA, to prevent abrasion. In further embodiments, surfaces within the fluid circuit are made as smooth as possible. In further embodiments, flow obstructions such as 90° pipe bends are avoided.

[0069] In some embodiments of the plant, a number of hydrogen sensors are provided to monitor that the explosion limit of the gas phase is not exceeded. Hydrogen is produced when black mass comes into contact with acid. The leaching reactor therefore is inertized, e.g., with nitrogen or argon. Hydrogen is also produced when black mass comes into contact with water. The reaction is slow but detectable. For this reason, the mixing vessel also is inertized with nitrogen. If the hydrogen sensors detect an increased hydrogen concentration locally, i.e., if the inertization has broken down in the mixing vessel or the leaching reactor, trigger an alarm is triggered in the PLS, and measures are taken to restore the safe state, e.g., by switching off the feed in the mixing vessel or the leaching reactor.

[0070] Detailed description of the drawing

[0071] Figure 1 shows a plant for processing black mass according to an embodiment of the invention.

[0072] A confined space 100 within the plant comprises an atmosphere with reduced atmospheric pressure and controlled humidity. Within the confined space 100, a first mixing vessel 120 is provided. The first mixing vessel 120 receives water 112 and particulate black mass 111 from a storage container 110, e.g., a big bag, placed in the confined space 100 by means of a conveyor (not shown) and mixes them using a mechanical stirrer 121 to produce an aqueous suspension of black mass particles.

[0073] The aqueous suspension of black mass particles is pumped from the mixing vessel 120 into a series of first storage tanks 130 wherein the suspension is constantly agitated. In the example shown in Fig. 1 , three first storage tanks 130 are provided which are arranged in parallel downstream the mixing vessel 120. A second storage tank 140 and a third storage tank 150 are configured to receive aqueous suspensions of CAM particles and MHP particles, respectively.

[0074] The first mixing vessel 120 also can be used to produce an aqueous suspension of CAM particles, which is then pumped from the mixing vessel 120 into the second storage tank 140. The aqueous suspension of MHP particles is produced in a second mixing vessel 160 located in the confined space 100, and subsequently is pumped from the mixing vessel 120 into the third storage tank 150.

[0075] The first storage tanks 130, the second storage tank 140, and the third storage tank 150 are located upstream of a leaching reactor 170 and connected to the leaching reactor 170. Aqueous suspensions from the first storage tanks 130, the second storage tank 140, and the third storage tank 150 can be dosed into the leaching reactor 170 through a series of pipes and valves.

[0076] List of reference numerals

[0077] 100 confined space

[0078] 110 storage container

[0079] 111 particulate black mass 112 water

[0080] 120 first mixing vessel

[0081] 121 stirrer

[0082] 130 first storage tanks

[0083] 140 second storage tank 150 third storage tank

[0084] 160 second mixing vessel

[0085] 170 leaching reactor

Claims

BASF SE B25.184P-WO67056 Ludwigshafen am Rhein 25.09.2025 / lg / np / jlClaims1. A method for processing black mass derived from lithium ion batteries, comprising providing particulate black mass (111 ) in a storage container (110) placed within a confined space (100) featuring featuring reduced atmospheric pressure and controlled atmospheric humidity, conveying particulate black mass from the storage container (110) into a mixing vessel (120) located within the confined space (100), mixing the particulate black mass (111 ) and water (112) in the mixing vessel (120) with stirring to produce an aqueous suspension of black mass particles, transferring the suspension of black mass particles into one or more storage tanks (130), continuously keeping the suspension of black mass particles in motion in the storage tank(s) (130) by stirring and / or recirculation using a suitable pump system.

2. The process of claim 1 , wherein the solids content of the aqueous suspension of black mass particles is from 20 wt% to 50 wt%, relative to the total weight of the aqueous suspension of black mass particles.

3. The process of claim 1 or 2, wherein the atmospheric pressure of the controlled atmosphere within the confined space (100) is lower than the ambient pressure outside the confined space (100), and the atmospheric humidity within the confined space (100) is kept within a range of from 45% to 20% relative humidity.

4. The process of any one of claims 1 to 3, further comprising dosing the suspension of black mass particles from the one or more storage tank(s) (130) into a leaching reactor (160), optionally dosing cathode active material (CAM) and / or mixed metal hydroxide precipitate (MHP) into theleaching reactor (160), adding an acid to the leaching reactor (160), and producing an aqueous acidic solution containing valuable metals leached from the black mass.

5. The process of any one of claims 1 to 4, wherein the flow velocity of the suspension of black mass particles is kept within a range of from 0.9 m / s to 2.3 m / s.

6. The process of any one of claims 1 to 5, wherein the mixing vessel (120) and the leaching reactor (160) are inertized with nitrogen or argon.

7. The process of any one of claims 1 to 6, further comprising measuring the pH value of the suspension of black mass particles in the storage tank(s) (130).

8. The process of any one of claims 1 to 7, further comprising measuring the redox potential of the suspension of black mass particles in the storage tank(s) (130).

9. A plant for processing black mass comprising means for safely conveying particulate black mass (111 ) from a storage container (110) into a mixing vessel (120) configured for mixing the black mass and water, a mixing vessel (120) comprising means (121 ) for agitating the vessel contents, at least three storage tanks (130, 140, 150) configured for storing an aqueous suspension of particles, each storage tank (130, 140, 150) comprising means for agitating the storage tank contents, wherein the storage container (110), the means for safely conveying black mass powder from the storage container (110) into a mixing vessel (120), and the mixing vessel (120) comprising means (121) for agitating the vessel contents are located within a confined space (100) featuring reduced atmospheric pressure and controlled atmospheric humidity.

10. The plant of claim 9, wherein the at least three storage tanks (130, 140, 150) are located outside the confined space (100) featuring reduced atmospheric pressure and controlled atmospheric humidity.11 . The plant of claim 9 or 10, additionally comprising a leaching reactor (170) located outside the confined space (100) featuring reduced atmospheric pressure and controlled atmospheric humidity.

12. The plant of any one of claims 9 to 11 , wherein the means for safely conveying particulate black mass (111 ) from a storage container (110) into a mixing vessel (120) comprise a pneumatic transfer cyclone with a suction lance.

13. The plant of any one of claims 9 to 12, wherein the means for agitating the contents of the mixing vessel (120) comprise a mechanical stirrer.

14. The plant of any one of claims 9 to 13, wherein the means for agitating the contents of the storage tank(s) (130, 140, 150) comprise a circulation pump.

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